Answer:
A) 
B) 
Explanation:
Given:
mass of car, 
A)
frequency of spring oscillation, 
We knkow the formula for spring oscillation frequency:




Now as we know that the springs are in parallel and their stiffness constant gets added up in parallel.
<u>So, the stiffness of each spring is (as they are identical):</u>



B)
given that 4 passengers of mass 70 kg each are in the car, then the oscillation frequency:



Answer:
The magnitude and direction of the acceleration of the particle is 
Explanation:
Given that,
Mass 
Velocity 
Charge 
Magnetic field 
We need to calculate the acceleration of the particle
Formula of the acceleration is defined as


We need to calculate the value of 


Now, put the all values into the acceleration 's formula


Negative sign shows the opposite direction.
Hence, The magnitude and direction of the acceleration of the particle is 
The IMA of the pulley shown is 2.